IAS 2011: Studies Prove Treatment Really is Prevention

IAS 2011: Studies Prove Treatment Really is Prevention

Monday at the International AIDS Society conference in Rome, an expanded session featured information on the HPTN 052 study, the Partners PrEP Study, and the Centers for Disease Control’s TDF2 study presented in a joint session titled Treatment Is Prevention: The Proof Is Here, on Monday. The results of these trials will fundamentally change the way we think about HIV prevention and treatment, although implementation of these approaches will likely prove as challenging as ever.

HPTN 052, sponsored by the HIV Prevention Trials Network, was the first randomized clinical trial to definitively indicate that an HIV-infected individual can reduce sexual transmission of HIV to an uninfected partner by beginning antiretroviral therapy sooner. The study involved 1,763 HIV-serodiscordant couples at 13 sites across Africa, Asia, and the Americas. The trial results were initially released in May 2011 on the recommendation of an independent data and safety monitoring board (DSMB) and Monday’s session was the first full presentation of the trial data.

Due to the strong HIV prevention effect seen in the Partner’s PrEP Study, the trial’s DSMB recommended that the study results be made public and the placebo arm of the study discontinued. The study, led by the University of Washington’s International Clinical Research Center, looked at 4,758 HIV serodiscordant couples at nine sites in Kenya and Uganda and involved providing medication to the HIV-negative partner. The results were announced on July 13. Through May 31, 2011, a total of 78 HIV infections occurred in the study: 18 among those assigned TDF, 13 among those assigned to FTC/TDF, and 47 among those assigned placebo. Thus, those who received TDF had an average of 62% fewer HIV infections (95% CI 34 to 78%, p=0.0003) and those who received FTC/TDF had 73% fewer HIV infections (95% CI 49 to 85%, p

The TDF2 study results were also released last week in conjunction with the Partners PrEP Study. The study involved over 1,200 participants at two sites in Botswana. Conducted in partnership with the Botswana Ministry of Health, the study found that a once-daily tablet containing tenofovir disoproxil fumarate and emtricitabine (TDF/FTC, known by the brand name Truvada) reduced the risk of acquiring HIV infection by roughly 63 percent overall in the study population of uninfected heterosexual men and women.

These last two studies are the first to show that a daily oral dose of antiretroviral drugs used to treat HIV infection can reduce HIV acquisition among uninfected individuals exposed to the virus through heterosexual sex, and the first study proves conclusively that HIV positive persons receiving effective HIV treatment reduce their infectiousness substantially.

While the benefits were long suspected, these clinical trials were the necessary next steps to prove that treatment really is prevention. At MSH, our goal now is to determine how best to implement this new found knowledge into our existing programs to provide the most comprehensive benefits to the people we serve, no small feat in an era of tightening resources.